high mass- explode as a supernova either a -neutron star or - collapse and become a black hole

What is a planetary nebula? With what stage of stellar evolution is it associated with?

when a star reaches the horizontal branch and then becomes a red giant agian The core never becomes hot enough to fuse carbon and it brightens until its envelope is ejected and forms a planetary nebula

What are white dwarfs and what is their ultimate fate?

white dwarfs occur then the core becomes very small but shines brightly by only stored heat

Eventually will become a black dwarf as it continues to cool and dim

under what circumstance will a bianary star produce a nova?

a nova is produced when i white dwarf becomes explosively active and suddenly appear in the night sky. lasts for a perios of 3 days.

(extra matter from red giant wraps around white dwarf)

What occurs in a massive star to cause it to explode?

1. neutrino pressure

2. fusion of infalling material

(type 2 supernova explosion)

What are observational difference between type 1 and type 2 supernova?

type 1- very little hydrogen and light curves

type 2- hydrogen rich characteristic "plaleu" in the light curve few months after the maximum

How do the mechanism that cause Type 1 and Type 2 supernova explain their observed difference?

type 2- stellar envelope expanding and cooling as it is blown into space by a shockwave sweeping up from below